the following seems to work for using github:
DISTNAME= fail2ban-fail2ban-sdist-0.8.5-0-g6c07999
#filename github would eventually give you without .tar.gz
MASTER_SITES=
https://nodeload.github.com/fail2ban/fail2ban/tarball/sdist/0.8.5?
#use ? to stop the url -- in this case the tag name is 'sdist/0.8.5'
so don't let the extra / confuse you